Vast felling and mulching operations are often performed with heavy-duty brush cutters. These brush cutters often have heavy-duty cutting heads removeably or permanently fixed on self-propelled vehicles. These cutting heads typically include a rotatable horizontal drum or roller upon which is mounted a plurality of cutting elements (i.e. cutting teeth). In operation, the rotation of the drum causes the cutting teeth to shred wood, debris and the like.
The cutting teeth are typically fixed to the outer surface of the drum via mounting blocks. Different mounting block configurations presently exist. For example, U.S. Pat. No. 5,873,534 describes a cutter tooth holder assembly for mounting about the curved surface of a rotatable cutter drum. The cutter tooth holder assembly includes a tooth holder for holding a cutter tooth and a mounting plate for attaching the tooth holder to the drum. The mounting plate has a generally concave surface for engaging the curved surface of the drum, and a top surface with a circumferentially extending tooth-locking groove formed along the entire length of the plate. The mounting plate is permanently attached to the drum by welding. The tooth holder has a generally square cross-section and is positioned in the tooth-locking groove formed within the mounting plate and welded in place. The tooth holder has a bore formed therein that is adapted to receive a cylindrical connector portion of the cutter tooth. The cutter tooth is generally polygonal with a plurality of cutting tips. When mounted within the tooth-locking groove one of the cutting tips is retained within the angled wall defining the tooth-locking groove thereby preventing rotational movement of the cutter tooth during operation of the brush cutter head.
While generally functional, the foregoing cutter tooth holder assembly tends to suffer from several drawbacks. First, to be able to withstand the high forces to which they are subjected, the assembly tends to be relatively large and heavy thereby requiring a substantial power draw. Second, the assembly remains unprotected from repeated contact with rocks or large trees. This exposure tends to make the assembly more prone to excessive wear and/or being damaged or broken off completely. As a result, this type of assembly requires costly servicing and replacement, the frequency of which tends to adversely impact the productivity of the brush cutter.
To address these shortcomings, certain known brush cutter heads have been provided with mounting block protection means. One such brush cutter head is described in U.S. Pat. No. 6,764,035. This patent discloses a brush cutter that has a cylindrical support base and a within the station plurality of cutting tooth mounting blocks fastened to the outer surface of the base. The bottom surface of each mounting block is concavely curved to match the radius of the base thereby allowing each mounting block to be welded onto the base with its bottom surface flush with the outer surface of the base. Each mounting block carries a cutting tooth on its front face. To protect the mounting blocks from rocks and large trees, each mounting block is provided with a protective collar. Each protective collar is welded to the outer surface of the base and extends radially therefrom, transverse to the longitudinal axis of the base. Each collar terminates circumferentially a short distance from the front face of the mounting block with which it is associated to provide a front clearance space. The opposed end of the collar is welded to the back face of the associated mounting block to strengthen it.
While the mounting block described in U.S. Pat. No. 6,764,035 is a general improvement over the cutting tooth holder assembly of U.S. Pat. No. 5,873,534, its monolithic construction tends to make it relatively heavy and thus not well-suited for use in light-duty brush cutters where improved power utilization and reduced power consumption are a priority.
In light of the foregoing, it would be advantageous to have a brush cutting head provided with a mounting assembly that is relatively light, simply constructed and generally less prone to damage from impact with hard objects. Such a brush cutting head would tend to consume less power and be suitable for use in light-duty brush cutters.